document_title: Fungus

question_text: which group of fungi do the mushrooms belong to

question_tokens: which group of fungi do the mushrooms belong to

text: Fungus

text: Etymology

text: The English word fungus is directly adopted from the Latin fungus (mushroom), used in the writings of Horace and Pliny.[7] This in turn is derived from the Greek word sphongos (σφόγγος "sponge"), which refers to the macroscopic structures and morphology of mushrooms and molds;[8] the root is also used in other languages, such as the German Schwamm ("sponge") and Schimmel ("mold").[9] The use of the word mycology, which is derived from the Greek mykes (μύκης "mushroom") and logos (λόγος "discourse"),[10] to denote the scientific study of fungi is thought to have originated in 1836 with English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5.[8] A group of all the fungi present in a particular area or geographic region is known as mycobiota (plural noun, no singular), e.g., "the mycobiota of Ireland".[11]

text: Characteristics

text: Hyphal wallSeptumMitochondrionVacuoleErgosterol crystalRibosomeNucleusEndoplasmic reticulumLipid bodyPlasma membraneSpitzenkörperGolgi apparatus

tag: ol

text: Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are mainly immobile, and have similarities in general morphology and growth habitat. Like plants, fungi often grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago (around the start of the Neoproterozoic Era).[12][13] Some morphological, biochemical, and genetic features are shared with other organisms, while others are unique to the fungi, clearly separating them from the other kingdoms:

text: Shared features:

text:
With other eukaryotes: Fungal cells contain membrane-bound nuclei with chromosomes that contain DNA with noncoding regions called introns and coding regions called exons. Fungi have membrane-bound cytoplasmic organelles such as mitochondria, sterol-containing membranes, and ribosomes of the 80S type.[14] They have a characteristic range of soluble carbohydrates and storage compounds, including sugar alcohols (e.g., mannitol), disaccharides, (e.g., trehalose), and polysaccharides (e.g., glycogen, which is also found in animals[15]).
With animals: Fungi lack chloroplasts and are heterotrophic organisms and so require preformed organic compounds as energy sources.[16]
With plants: Fungi have a cell wall[17] and vacuoles.[18] They reproduce by both sexual and asexual means, and like basal plant groups (such as ferns and mosses) produce spores. Similar to mosses and algae, fungi typically have haploid nuclei.[19]
With euglenoids and bacteria: Higher fungi, euglenoids, and some bacteria produce the amino acid L-lysine in specific biosynthesis steps, called the α-aminoadipate pathway.[20][21]
The cells of most fungi grow as tubular, elongated, and thread-like (filamentous) structures called hyphae, which may contain multiple nuclei and extend by growing at their tips. Each tip contains a set of aggregated vesicles—cellular structures consisting of proteins, lipids, and other organic molecules—called the Spitzenkörper.[22] Both fungi and oomycetes grow as filamentous hyphal cells.[23] In contrast, similar-looking organisms, such as filamentous green algae, grow by repeated cell division within a chain of cells.[15] There are also single-celled fungi (yeasts) that do not form hyphae, and some fungi have both hyphal and yeast forms.[24]
In common with some plant and animal species, more than 70 fungal species display bioluminescence.[25]

text: Unique features:

text:
Some species grow as unicellular yeasts that reproduce by budding or binary fission. Dimorphic fungi can switch between a yeast phase and a hyphal phase in response to environmental conditions.[24]
The fungal cell wall is composed of glucans and chitin; while glucans are also found in plants and chitin in the exoskeleton of arthropods,[26][27] fungi are the only organisms that combine these two structural molecules in their cell wall. Unlike those of plants and oomycetes, fungal cell walls do not contain cellulose.[28]

text: Most fungi lack an efficient system for the long-distance transport of water and nutrients, such as the xylem and phloem in many plants. To overcome this limitation, some fungi, such as Armillaria, form rhizomorphs,[29] which resemble and perform functions similar to the roots of plants. As eukaryotes, fungi possess a biosynthetic pathway for producing terpenes that uses mevalonic acid and pyrophosphate as chemical building blocks.[30] Plants and some other organisms have an additional terpene biosynthesis pathway in their chloroplasts, a structure fungi and animals do not have.[31] Fungi produce several secondary metabolites that are similar or identical in structure to those made by plants.[30] Many of the plant and fungal enzymes that make these compounds differ from each other in sequence and other characteristics, which indicates separate origins and convergent evolution of these enzymes in the fungi and plants.[30][32]

text: Diversity

text: Fungi have a worldwide distribution, and grow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentrations[33] or ionizing radiation,[34] as well as in deep sea sediments.[35] Some can survive the intense UV and cosmic radiation encountered during space travel.[36] Most grow in terrestrial environments, though several species live partly or solely in aquatic habitats, such as the chytrid fungus Batrachochytrium dendrobatidis, a parasite that has been responsible for a worldwide decline in amphibian populations. This organism spends part of its life cycle as a motile zoospore, enabling it to propel itself through water and enter its amphibian host.[37] Other examples of aquatic fungi include those living in hydrothermal areas of the ocean.[38]

text: Around 120,000 species of fungi have been described by taxonomists,[39] but the global biodiversity of the fungus kingdom is not fully understood.[39] A 2017 estimate suggests there may be between 2.2 and 3.8 million species.[5] In mycology, species have historically been distinguished by a variety of methods and concepts. Classification based on morphological characteristics, such as the size and shape of spores or fruiting structures, has traditionally dominated fungal taxonomy.[40] Species may also be distinguished by their biochemical and physiological characteristics, such as their ability to metabolize certain biochemicals, or their reaction to chemical tests. The biological species concept discriminates species based on their ability to mate. The application of molecular tools, such as DNA sequencing and phylogenetic analysis, to study diversity has greatly enhanced the resolution and added robustness to estimates of genetic diversity within various taxonomic groups.[41]

text: Mycology

text: Mycology is the branch of biology concerned with the systematic study of fungi, including their genetic and biochemical properties, their taxonomy, and their use to humans as a source of medicine, food, and psychotropic substances consumed for religious purposes, as well as their dangers, such as poisoning or infection. The field of phytopathology, the study of plant diseases, is closely related because many plant pathogens are fungi.[42]

text: The use of fungi by humans dates back to prehistory; Ötzi the Iceman, a well-preserved mummy of a 5,300-year-old Neolithic man found frozen in the Austrian Alps, carried two species of polypore mushrooms that may have been used as tinder (Fomes fomentarius), or for medicinal purposes (Piptoporus betulinus).[43] Ancient peoples have used fungi as food sources–often unknowingly–for millennia, in the preparation of leavened bread and fermented juices. Some of the oldest written records contain references to the destruction of crops that were probably caused by pathogenic fungi.[44]

text: History

text: Mycology is a relatively new science that became systematic after the development of the microscope in the 17th century. Although fungal spores were first observed by Giambattista della Porta in 1588, the seminal work in the development of mycology is considered to be the publication of Pier Antonio Micheli's 1729 work Nova plantarum genera.[45] Micheli not only observed spores but also showed that, under the proper conditions, they could be induced into growing into the same species of fungi from which they originated.[46] Extending the use of the binomial system of nomenclature introduced by Carl Linnaeus in his Species plantarum (1753), the Dutch Christian Hendrik Persoon (1761–1836) established the first classification of mushrooms with such skill as to be considered a founder of modern mycology. Later, Elias Magnus Fries (1794–1878) further elaborated the classification of fungi, using spore color and microscopic characteristics, methods still used by taxonomists today. Other notable early contributors to mycology in the 17th–19th and early 20th centuries include Miles Joseph Berkeley, August Carl Joseph Corda, Anton de Bary, the brothers Louis René and Charles Tulasne, Arthur H. R. Buller, Curtis G. Lloyd, and Pier Andrea Saccardo. The 20th century has seen a modernization of mycology that has come from advances in biochemistry, genetics, molecular biology, and biotechnology. The use of DNA sequencing technologies and phylogenetic analysis has provided new insights into fungal relationships and biodiversity, and has challenged traditional morphology-based groupings in fungal taxonomy.[47]

text: Morphology

text: Microscopic structures

text: hyphaconidiophorephialideconidiasepta

text: Most fungi grow as hyphae, which are cylindrical, thread-like structures 2–10 µm in diameter and up to several centimeters in length. Hyphae grow at their tips (apices); new hyphae are typically formed by emergence of new tips along existing hyphae by a process called branching, or occasionally growing hyphal tips fork, giving rise to two parallel-growing hyphae.[48] Hyphae also sometimes fuse when they come into contact, a process called hyphal fusion (or anastamosis). These growth processes lead to the development of a mycelium, an interconnected network of hyphae.[24] Hyphae can be either septate or coenocytic. Septate hyphae are divided into compartments separated by cross walls (internal cell walls, called septa, that are formed at right angles to the cell wall giving the hypha its shape), with each compartment containing one or more nuclei; coenocytic hyphae are not compartmentalized.[49] Septa have pores that allow cytoplasm, organelles, and sometimes nuclei to pass through; an example is the dolipore septum in fungi of the phylum Basidiomycota.[50] Coenocytic hyphae are in essence multinucleate supercells.[51]

text: Many species have developed specialized hyphal structures for nutrient uptake from living hosts; examples include haustoria in plant-parasitic species of most fungal phyla, and arbuscules of several mycorrhizal fungi, which penetrate into the host cells to consume nutrients.[52]

text: Although fungi are opisthokonts—a grouping of evolutionarily related organisms broadly characterized by a single posterior flagellum—all phyla except for the chytrids have lost their posterior flagella.[53] Fungi are unusual among the eukaryotes in having a cell wall that, in addition to glucans (e.g., β-1,3-glucan) and other typical components, also contains the biopolymer chitin.[54]

text: Macroscopic structures

text: Fungal mycelia can become visible to the naked eye, for example, on various surfaces and substrates, such as damp walls and spoiled food, where they are commonly called molds. Mycelia grown on solid agar media in laboratory petri dishes are usually referred to as colonies. These colonies can exhibit growth shapes and colors (due to spores or pigmentation) that can be used as diagnostic features in the identification of species or groups.[55] Some individual fungal colonies can reach extraordinary dimensions and ages as in the case of a clonal colony of Armillaria solidipes, which extends over an area of more than 900 ha (3.5 square miles), with an estimated age of nearly 9,000 years.[56]

text: The apothecium—a specialized structure important in sexual reproduction in the ascomycetes—is a cup-shaped fruit body that is often macroscopic and holds the hymenium, a layer of tissue containing the spore-bearing cells.[57] The fruit bodies of the basidiomycetes (basidiocarps) and some ascomycetes can sometimes grow very large, and many are well known as mushrooms.

text: Growth and physiology

text: The growth of fungi as hyphae on or in solid substrates or as single cells in aquatic environments is adapted for the efficient extraction of nutrients, because these growth forms have high surface area to volume ratios.[58] Hyphae are specifically adapted for growth on solid surfaces, and to invade substrates and tissues.[59] They can exert large penetrative mechanical forces; for example, many plant pathogens, including Magnaporthe grisea, form a structure called an appressorium that evolved to puncture plant tissues.[60] The pressure generated by the appressorium, directed against the plant epidermis, can exceed 8 megapascals (1,200 psi).[60] The filamentous fungus Paecilomyces lilacinus uses a similar structure to penetrate the eggs of nematodes.[61]

text: The mechanical pressure exerted by the appressorium is generated from physiological processes that increase intracellular turgor by producing osmolytes such as glycerol.[62] Adaptations such as these are complemented by hydrolytic enzymes secreted into the environment to digest large organic molecules—such as polysaccharides, proteins, and lipids—into smaller molecules that may then be absorbed as nutrients.[63][64][65] The vast majority of filamentous fungi grow in a polar fashion (extending in one direction) by elongation at the tip (apex) of the hypha.[66] Other forms of fungal growth include intercalary extension (longitudinal expansion of hyphal compartments that are below the apex) as in the case of some endophytic fungi,[67] or growth by volume expansion during the development of mushroom stipes and other large organs.[68] Growth of fungi as multicellular structures consisting of somatic and reproductive cells—a feature independently evolved in animals and plants[69]—has several functions, including the development of fruit bodies for dissemination of sexual spores (see above) and biofilms for substrate colonization and intercellular communication.[70]

text: The fungi are traditionally considered heterotrophs, organisms that rely solely on carbon fixed by other organisms for metabolism. Fungi have evolved a high degree of metabolic versatility that allows them to use a diverse range of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol.[71][72] In some species the pigment melanin may play a role in extracting energy from ionizing radiation, such as gamma radiation. This form of "radiotrophic" growth has been described for only a few species, the effects on growth rates are small, and the underlying biophysical and biochemical processes are not well known.[34] This process might bear similarity to CO2 fixation via visible light, but instead uses ionizing radiation as a source of energy.[73]

text: Reproduction

text: Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms.[74] It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the life cycle of a species, the teleomorph and the anamorph.[75] Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing propagules.

text: Asexual reproduction

text: Asexual reproduction occurs via vegetative spores (conidia) or through mycelial fragmentation. Mycelial fragmentation occurs when a fungal mycelium separates into pieces, and each component grows into a separate mycelium. Mycelial fragmentation and vegetative spores maintain clonal populations adapted to a specific niche, and allow more rapid dispersal than sexual reproduction.[76] The "Fungi imperfecti" (fungi lacking the perfect or sexual stage) or Deuteromycota comprise all the species that lack an observable sexual cycle.[77] Deuteromycota is not an accepted taxonomic clade, and is now taken to mean simply fungi that lack a known sexual stage.

text: Sexual reproduction

text: Sexual reproduction with meiosis has been directly observed in all fungal phyla except Glomeromycota [78] (genetic analysis suggests meiosis in Glomeromycota as well). It differs in many aspects from sexual reproduction in animals or plants. Differences also exist between fungal groups and can be used to discriminate species by morphological differences in sexual structures and reproductive strategies.[79][80] Mating experiments between fungal isolates may identify species on the basis of biological species concepts.[80] The major fungal groupings have initially been delineated based on the morphology of their sexual structures and spores; for example, the spore-containing structures, asci and basidia, can be used in the identification of ascomycetes and basidiomycetes, respectively. Some species may allow mating only between individuals of opposite mating type, whereas others can mate and sexually reproduce with any other individual or itself. Species of the former mating system are called heterothallic, and of the latter homothallic.[81]

text: Most fungi have both a haploid and a diploid stage in their life cycles. In sexually reproducing fungi, compatible individuals may combine by fusing their hyphae together into an interconnected network; this process, anastomosis, is required for the initiation of the sexual cycle. Many ascomycetes and basidiomycetes go through a dikaryotic stage, in which the nuclei inherited from the two parents do not combine immediately after cell fusion, but remain separate in the hyphal cells (see heterokaryosis).[82]

text: In ascomycetes, dikaryotic hyphae of the hymenium (the spore-bearing tissue layer) form a characteristic hook at the hyphal septum. During cell division, formation of the hook ensures proper distribution of the newly divided nuclei into the apical and basal hyphal compartments. An ascus (plural asci) is then formed, in which karyogamy (nuclear fusion) occurs. Asci are embedded in an ascocarp, or fruiting body. Karyogamy in the asci is followed immediately by meiosis and the production of ascospores. After dispersal, the ascospores may germinate and form a new haploid mycelium.[83]

text: Sexual reproduction in basidiomycetes is similar to that of the ascomycetes. Compatible haploid hyphae fuse to produce a dikaryotic mycelium. However, the dikaryotic phase is more extensive in the basidiomycetes, often also present in the vegetatively growing mycelium. A specialized anatomical structure, called a clamp connection, is formed at each hyphal septum. As with the structurally similar hook in the ascomycetes, the clamp connection in the basidiomycetes is required for controlled transfer of nuclei during cell division, to maintain the dikaryotic stage with two genetically different nuclei in each hyphal compartment.[84] A basidiocarp is formed in which club-like structures known as basidia generate haploid basidiospores after karyogamy and meiosis.[85] The most commonly known basidiocarps are mushrooms, but they may also take other forms (see Morphology section).

text: In glomeromycetes (formerly zygomycetes), haploid hyphae of two individuals fuse, forming a gametangium, a specialized cell structure that becomes a fertile gamete-producing cell. The gametangium develops into a zygospore, a thick-walled spore formed by the union of gametes. When the zygospore germinates, it undergoes meiosis, generating new haploid hyphae, which may then form asexual sporangiospores. These sporangiospores allow the fungus to rapidly disperse and germinate into new genetically identical haploid fungal mycelia.[86]

text: Spore dispersal

text: Both asexual and sexual spores or sporangiospores are often actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of the spores from the reproductive structures as well as traveling through the air over long distances.

text: Specialized mechanical and physiological mechanisms, as well as spore surface structures (such as hydrophobins), enable efficient spore ejection.[87] For example, the structure of the spore-bearing cells in some ascomycete species is such that the buildup of substances affecting cell volume and fluid balance enables the explosive discharge of spores into the air.[88] The forcible discharge of single spores termed ballistospores involves formation of a small drop of water (Buller's drop), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g;[89] the net result is that the spore is ejected 0.01–0.02 cm, sufficient distance for it to fall through the gills or pores into the air below.[90] Other fungi, like the puffballs, rely on alternative mechanisms for spore release, such as external mechanical forces. The bird's nest fungi use the force of falling water drops to liberate the spores from cup-shaped fruiting bodies.[91] Another strategy is seen in the stinkhorns, a group of fungi with lively colors and putrid odor that attract insects to disperse their spores.[92]

text: Other sexual processes

text: Besides regular sexual reproduction with meiosis, certain fungi, such as those in the genera Penicillium and Aspergillus, may exchange genetic material via parasexual processes, initiated by anastomosis between hyphae and plasmogamy of fungal cells.[93] The frequency and relative importance of parasexual events is unclear and may be lower than other sexual processes. It is known to play a role in intraspecific hybridization[94] and is likely required for hybridization between species, which has been associated with major events in fungal evolution.[95]

text: Evolution

text: In contrast to plants and animals, the early fossil record of the fungi is meager. Factors that likely contribute to the under-representation of fungal species among fossils include the nature of fungal fruiting bodies, which are soft, fleshy, and easily degradable tissues and the microscopic dimensions of most fungal structures, which therefore are not readily evident. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble extant fungi.[96] Often recovered from a permineralized plant or animal host, these samples are typically studied by making thin-section preparations that can be examined with light microscopy or transmission electron microscopy.[97] Researchers study compression fossils by dissolving the surrounding matrix with acid and then using light or scanning electron microscopy to examine surface details.[98]

text: The earliest fossils possessing features typical of fungi date to the Paleoproterozoic era, some 2,400 million years ago (Ma); these multicellular benthic organisms had filamentous structures capable of anastomosis.[99] Other studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups.[100] For much of the Paleozoic Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant chytrids in having flagellum-bearing spores.[101] The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization.[102] Recent (2009) studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times.[103]

text: It is presumed that the fungi colonized the land during the Cambrian (542–488.3 Ma), long before land plants.[104] Fossilized hyphae and spores recovered from the Ordovician of Wisconsin (460 Ma) resemble modern-day Glomerales, and existed at a time when the land flora likely consisted of only non-vascular bryophyte-like plants.[105] Prototaxites, which was probably a fungus or lichen, would have been the tallest organism of the late Silurian. Fungal fossils do not become common and uncontroversial until the early Devonian (416–359.2 Ma), when they occur abundantly in the Rhynie chert, mostly as Zygomycota and Chytridiomycota.[104][106][107] At about this same time, approximately 400 Ma, the Ascomycota and Basidiomycota diverged,[108] and all modern classes of fungi were present by the Late Carboniferous (Pennsylvanian, 318.1–299 Ma).[109]

text: Lichen-like fossils have been found in the Doushantuo Formation in southern China dating back to 635–551 Ma.[110] Lichens formed a component of the early terrestrial ecosystems, and the estimated age of the oldest terrestrial lichen fossil is 400 Ma;[111] this date corresponds to the age of the oldest known sporocarp fossil, a Paleopyrenomycites species found in the Rhynie Chert.[112] The oldest fossil with microscopic features resembling modern-day basidiomycetes is Palaeoancistrus, found permineralized with a fern from the Pennsylvanian.[113] Rare in the fossil record are the Homobasidiomycetes (a taxon roughly equivalent to the mushroom-producing species of the Agaricomycetes). Two amber-preserved specimens provide evidence that the earliest known mushroom-forming fungi (the extinct species Archaeomarasmius leggetti) appeared during the late Cretaceous, 90 Ma.[114][115]

text: Some time after the Permian–Triassic extinction event (251.4 Ma), a fungal spike (originally thought to be an extraordinary abundance of fungal spores in sediments) formed, suggesting that fungi were the dominant life form at this time, representing nearly 100% of the available fossil record for this period.[116] However, the relative proportion of fungal spores relative to spores formed by algal species is difficult to assess,[117] the spike did not appear worldwide,[118][119] and in many places it did not fall on the Permian–Triassic boundary.[120]

text: 65 million years ago, immediately after the Cretaceous–Paleogene extinction that famously killed off most dinosaurs, there is a dramatic increase in evidence of fungi, apparently the death of most plant and animal species leading to a huge fungal bloom like "a massive compost heap".[121]

text: Taxonomy

text: Although commonly included in botany curricula and textbooks, fungi are more closely related to animals than to plants and are placed with the animals in the monophyletic group of opisthokonts.[122] Analyses using molecular phylogenetics support a monophyletic origin of fungi.[41] The taxonomy of fungi is in a state of constant flux, especially due to recent research based on DNA comparisons. These current phylogenetic analyses often overturn classifications based on older and sometimes less discriminative methods based on morphological features and biological species concepts obtained from experimental matings.[123]

text: There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards. Efforts among researchers are now underway to establish and encourage usage of a unified and more consistent nomenclature.[41][124] Fungal species can also have multiple scientific names depending on their life cycle and mode (sexual or asexual) of reproduction. Web sites such as Index Fungorum and ITIS list current names of fungal species (with cross-references to older synonyms).

text: The 2007 classification of Kingdom Fungi is the result of a large-scale collaborative research effort involving dozens of mycologists and other scientists working on fungal taxonomy.[41] It recognizes seven phyla, two of which—the Ascomycota and the Basidiomycota—are contained within a branch representing subkingdom Dikarya, the most species rich and familiar group, including all the mushrooms, most food-spoilage molds, most plant pathogenic fungi, and the beer, wine, and bread yeasts. The accompanying cladogram depicts the major fungal taxa and their relationship to opisthokont and unikont organisms, based on the work of Philippe Silar,[125] "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research"[126] and Tedersoo et al. 2018.[127] The lengths of the branches are not proportional to evolutionary distances.

text:
Zoosporia

Rozellomyceta

Rozellomycota

Rozellomycetes

Microsporidiomycota

Mitosporidium

Paramicrosporidium

Nucleophaga

Metchnikovellea

Microsporea

Aphelidiomyceta

Aphelidiomycota

Aphelidiomycetes

Eumycota

Chytridiomyceta

Neocallimastigomycota

Neocallimastigomycetes

Chytridiomycota

Monoblepharomycotina

Hyaloraphidiomycetes

Monoblepharidomycetes

Sanchytriomycetes

Chytridiomycotina

Mesochytriomycetes

Chytridiomycetes

Amastigomycota

Blastocladiomyceta

Blastocladiomycota

Blastocladiomycetes

Physodermatomycetes

Zoopagomyceta

Basidiobolomycota

Basidiobolomycetes

Olpidiomycetes

Entomophthoromycota

Neozygitomycetes

Entomophthoromycetes

Kickxellomycota

Zoopagomycotina

Zoopagomycetes

Kickxellomycotina

Dimargaritomycetes

Kickxellomycetes

Mortierellomycota

Mortierellomycetes

Mucoromyceta

Calcarisporiellomycota

Calcarisporiellomycetes

Mucoromycota

Umbelopsidomycetes

Mucoromycetes

Symbiomycota

Glomeromycota

Paraglomeromycetes

Archaeosporomycetes

Glomeromycetes

Dikarya

Entorrhizomycota

Entorrhizomycetes

Basidiomycota

Ascomycota

text:
Basidiomycota

Pucciniomycotina

Tritirachiomycetes

Mixiomycetes

Agaricostilbomycetes

Cystobasidiomycetes

Classiculaceae

Microbotryomycetes

Cryptomycocolacomycetes

Atractiellomycetes

Pucciniomycetes

Orthomycotina

Ustilaginomycotina

Monilielliomycetes

Malasseziomycetes

Ustilaginomycetes

Exobasidiomycetes

Agaricomycotina

?Geminibasidiomycetes

?Wallemiomycetes

Bartheletiomycetes

Tremellomycetes

Dacrymycetes

Agaricomycetes

text:
Ascomycota

Taphrinomycotina

Neolectomycetes

Taphrinomycetes

Schizosaccharomyceta

Archaeorhizomycetes

Pneumocystidomycetes

Schizosaccharomycetes

Saccharomyceta

Saccharomycotina

Saccharomycetes

Pezizomycotina

?Thelocarpales

?Vezdaeales

?Lahmiales

?Triblidiales

Orbiliomycetes

Pezizomycetes

Leotiomyceta

Sordariomyceta

Xylonomycetes

Geoglossomycetes

Leotiomycetes

Laboulbeniomycetes

Sordariomycetes

Dothideomyceta

Coniocybomycetes

Lichinomycetes

Eurotiomycetes

Lecanoromycetes

Collemopsidiomycetes

Arthoniomycetes

Dothideomycetes

text: Taxonomic groups

text: The major phyla (sometimes called divisions) of fungi have been classified mainly on the basis of characteristics of their sexual reproductive structures. Currently, seven phyla are proposed: Microsporidia, Chytridiomycota, Blastocladiomycota, Neocallimastigomycota, Glomeromycota, Ascomycota, and Basidiomycota.[41]

text: Phylogenetic analysis has demonstrated that the Microsporidia, unicellular parasites of animals and protists, are fairly recent and highly derived endobiotic fungi (living within the tissue of another species).[101][128] One 2006 study concludes that the Microsporidia are a sister group to the true fungi; that is, they are each other's closest evolutionary relative.[129] Hibbett and colleagues suggest that this analysis does not clash with their classification of the Fungi, and although the Microsporidia are elevated to phylum status, it is acknowledged that further analysis is required to clarify evolutionary relationships within this group.[41]

text: The Chytridiomycota are commonly known as chytrids. These fungi are distributed worldwide. Chytrids and their close relatives Neocallimastigomycota and Blastocladiomycota (below) are the only fungi with active motility, producing zoospores that are capable of active movement through aqueous phases with a single flagellum, leading early taxonomists to classify them as protists. Molecular phylogenies, inferred from rRNA sequences in ribosomes, suggest that the Chytrids are a basal group divergent from the other fungal phyla, consisting of four major clades with suggestive evidence for paraphyly or possibly polyphyly.[130]

text: The Blastocladiomycota were previously considered a taxonomic clade within the Chytridiomycota. Recent molecular data and ultrastructural characteristics, however, place the Blastocladiomycota as a sister clade to the Zygomycota, Glomeromycota, and Dikarya (Ascomycota and Basidiomycota). The blastocladiomycetes are saprotrophs, feeding on decomposing organic matter, and they are parasites of all eukaryotic groups. Unlike their close relatives, the chytrids, most of which exhibit zygotic meiosis, the blastocladiomycetes undergo sporic meiosis.[101]

text: The Neocallimastigomycota were earlier placed in the phylum Chytridomycota. Members of this small phylum are anaerobic organisms, living in the digestive system of larger herbivorous mammals and in other terrestrial and aquatic environments enriched in cellulose (e.g., domestic waste landfill sites).[131] They lack mitochondria but contain hydrogenosomes of mitochondrial origin. As in the related chrytrids, neocallimastigomycetes form zoospores that are posteriorly uniflagellate or polyflagellate.[41]

text: Members of the Glomeromycota form arbuscular mycorrhizae, a form of mutualist symbiosis wherein fungal hyphae invade plant root cells and both species benefit from the resulting increased supply of nutrients. All known Glomeromycota species reproduce asexually.[78] The symbiotic association between the Glomeromycota and plants is ancient, with evidence dating to 400 million years ago.[132] Formerly part of the Zygomycota (commonly known as 'sugar' and 'pin' molds), the Glomeromycota were elevated to phylum status in 2001 and now replace the older phylum Zygomycota.[133] Fungi that were placed in the Zygomycota are now being reassigned to the Glomeromycota, or the subphyla incertae sedis Mucoromycotina, Kickxellomycotina, the Zoopagomycotina and the Entomophthoromycotina.[41] Some well-known examples of fungi formerly in the Zygomycota include black bread mold (Rhizopus stolonifer), and Pilobolus species, capable of ejecting spores several meters through the air.[134] Medically relevant genera include Mucor, Rhizomucor, and Rhizopus.

text: The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota.[40] These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This phylum includes morels, a few mushrooms and truffles, unicellular yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts (e.g. lichens). Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycete species have only been observed undergoing asexual reproduction (called anamorphic species), but analysis of molecular data has often been able to identify their closest teleomorphs in the Ascomycota.[135] Because the products of meiosis are retained within the sac-like ascus, ascomycetes have been used for elucidating principles of genetics and heredity (e.g., Neurospora crassa).[136]

text: Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust and smut fungi, which are major pathogens of grains. Other important basidiomycetes include the maize pathogen Ustilago maydis,[137] human commensal species of the genus Malassezia,[138] and the opportunistic human pathogen, Cryptococcus neoformans.[139]

text: Fungus-like organisms

text: Because of similarities in morphology and lifestyle, the slime molds (mycetozoans, plasmodiophorids, acrasids, Fonticula and labyrinthulids, now in Amoebozoa, Rhizaria, Excavata, Opisthokonta and Stramenopiles, respectively), water molds (oomycetes) and hyphochytrids (both Stramenopiles) were formerly classified in the kingdom Fungi, in groups like Mastigomycotina, Gymnomycota and Phycomycetes. The slime molds were studied also as protozoans, leading to a ambiregnal, duplicated taxonomy.

text: Unlike true fungi, the cell walls of oomycetes contain cellulose and lack chitin. Hyphochytrids have both chitin and cellulose. Slime molds lack a cell wall during the assimilative phase (except labyrinthulids, which have a wall of scales), and ingest nutrients by ingestion (phagocytosis, except labyrinthulids) rather than absorption (osmotrophy, as fungi, labyrinthulids, oomycetes and hyphochytrids). Neither water molds nor slime molds are closely related to the true fungi, and, therefore, taxonomists no longer group them in the kingdom Fungi. Nonetheless, studies of the oomycetes and myxomycetes are still often included in mycology textbooks and primary research literature.[140]

text: The Eccrinales and Amoebidiales are opisthokont protists, previously thought to be zygomycete fungi. Other groups now in Opisthokonta (e.g., Corallochytrium, Ichthyosporea) were also at given time classified as fungi. The genus Blastocystis, now in Stramenopiles, was originally classified as a yeast. Ellobiopsis, now in Alveolata, was considered a chytrid. The bacteria were also included in fungi in some classifications, as the group Schizomycetes.

text: The Rozellida clade, including the "ex-chytrid" Rozella, is a genetically disparate group known mostly from environmental DNA sequences that is a sister group to fungi. Members of the group that have been isolated lack the chitinous cell wall that is characteristic of fungi.

text: The nucleariids may be the next sister group to the eumycete clade, and as such could be included in an expanded fungal kingdom.[122]

text: Many Actinomycetales (Actinobacteria), a group with many filamentous bacteria, were also long believed to be fungi.

text: Ecology

text: Although often inconspicuous, fungi occur in every environment on Earth and play very important roles in most ecosystems. Along with bacteria, fungi are the major decomposers in most terrestrial (and some aquatic) ecosystems, and therefore play a critical role in biogeochemical cycles[141] and in many food webs. As decomposers, they play an essential role in nutrient cycling, especially as saprotrophs and symbionts, degrading organic matter to inorganic molecules, which can then re-enter anabolic metabolic pathways in plants or other organisms.[142][143]

text: Symbiosis

text: Many fungi have important symbiotic relationships with organisms from most if not all Kingdoms.[144][145][146] These interactions can be mutualistic or antagonistic in nature, or in the case of commensal fungi are of no apparent benefit or detriment to the host.[147][148][149]

text: With plants

text: Mycorrhizal symbiosis between plants and fungi is one of the most well-known plant–fungus associations and is of significant importance for plant growth and persistence in many ecosystems; over 90% of all plant species engage in mycorrhizal relationships with fungi and are dependent upon this relationship for survival.[150]

text: The mycorrhizal symbiosis is ancient, dating to at least 400 million years ago.[132] It often increases the plant's uptake of inorganic compounds, such as nitrate and phosphate from soils having low concentrations of these key plant nutrients.[142][151] The fungal partners may also mediate plant-to-plant transfer of carbohydrates and other nutrients. Such mycorrhizal communities are called "common mycorrhizal networks".[152] A special case of mycorrhiza is myco-heterotrophy, whereby the plant parasitizes the fungus, obtaining all of its nutrients from its fungal symbiont.[153] Some fungal species inhabit the tissues inside roots, stems, and leaves, in which case they are called endophytes.[154] Similar to mycorrhiza, endophytic colonization by fungi may benefit both symbionts; for example, endophytes of grasses impart to their host increased resistance to herbivores and other environmental stresses and receive food and shelter from the plant in return.[155]

text: With algae and cyanobacteria

text: Lichens are a symbiotic relationship between fungi and photosynthetic algae or cyanobacteria. The photosynthetic partner in the relationship is referred to in lichen terminology as a "photobiont". The fungal part of the relationship is composed mostly of various species of ascomycetes and a few basidiomycetes.[156] Lichens occur in every ecosystem on all continents, play a key role in soil formation and the initiation of biological succession,[157] and are prominent in some extreme environments, including polar, alpine, and semiarid desert regions.[158] They are able to grow on inhospitable surfaces, including bare soil, rocks, tree bark, wood, shells, barnacles and leaves.[159] As in mycorrhizas, the photobiont provides sugars and other carbohydrates via photosynthesis to the fungus, while the fungus provides minerals and water to the photobiont. The functions of both symbiotic organisms are so closely intertwined that they function almost as a single organism; in most cases the resulting organism differs greatly from the individual components. Lichenization is a common mode of nutrition for fungi; around 20% of fungi—between 17,500 and 20,000 described species—are lichenized.[160] Characteristics common to most lichens include obtaining organic carbon by photosynthesis, slow growth, small size, long life, long-lasting (seasonal) vegetative reproductive structures, mineral nutrition obtained largely from airborne sources, and greater tolerance of desiccation than most other photosynthetic organisms in the same habitat.[161]

text: With insects

text: Many insects also engage in mutualistic relationships with fungi. Several groups of ants cultivate fungi in the order Agaricales as their primary food source, while ambrosia beetles cultivate various species of fungi in the bark of trees that they infest.[162] Likewise, females of several wood wasp species (genus Sirex) inject their eggs together with spores of the wood-rotting fungus Amylostereum areolatum into the sapwood of pine trees; the growth of the fungus provides ideal nutritional conditions for the development of the wasp larvae.[163] At least one species of stingless bee has a relationship with a fungus in the genus Monascus, where the larvae consume and depend on fungus transferred from old to new nests.[164] Termites on the African savannah are also known to cultivate fungi,[144] and yeasts of the genera Candida and Lachancea inhabit the gut of a wide range of insects, including neuropterans, beetles, and cockroaches; it is not known whether these fungi benefit their hosts.[165] Fungi ingrowing dead wood are essential for xylophagous insects (e.g. woodboring beetles).[166][non-primary source needed] They deliver nutrients needed by xylophages to nutritionally scarce dead wood.[167][non-primary source needed]  Thanks to this nutritional enrichment the larvae of woodboring insect is able to grow and develop to adulthood.[166] The larvae of many families of fungicolous flies, particularly those within the superfamily Sciaroidea such as the Mycetophilidae and some Keroplatidae feed on fungal fruiting bodies and sterile mycorrhizae.[168]

text: As pathogens and parasites

text: Many fungi are parasites on plants, animals (including humans), and other fungi. Serious pathogens of many cultivated plants causing extensive damage and losses to agriculture and forestry include the rice blast fungus Magnaporthe oryzae,[169] tree pathogens such as Ophiostoma ulmi and Ophiostoma novo-ulmi causing Dutch elm disease[170] and Cryphonectria parasitica responsible for chestnut blight,[171] and plant pathogens in the genera Fusarium, Ustilago, Alternaria, and Cochliobolus.[148] Some carnivorous fungi, like Paecilomyces lilacinus, are predators of nematodes, which they capture using an array of specialized structures such as constricting rings or adhesive nets.[172] Many fungi that are plant pathogens, such as Magnaporthe oryzae, can switch from being biotrophic (parasitic on living plants) to being necrotrophic (feeding on the dead tissues of plants they have killed).[173]

text: Some fungi can cause serious diseases in humans, several of which may be fatal if untreated. These include aspergillosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, mycetomas, and paracoccidioidomycosis. Furthermore, persons with immuno-deficiencies are particularly susceptible to disease by genera such as Aspergillus, Candida, Cryptoccocus,[149][174][175] Histoplasma,[176] and Pneumocystis.[177] Other fungi can attack eyes, nails, hair, and especially skin, the so-called dermatophytic and keratinophilic fungi, and cause local infections such as ringworm and athlete's foot.[178] Fungal spores are also a cause of allergies, and fungi from different taxonomic groups can evoke allergic reactions.[179]

text: As targets of mycoparasites

text: The organisms which parasitize fungi are known as mycoparasitic organisms. Certain species of the genus Pythium, which are oomycetes, have potential as biocontrol agents against certain fungi.[180] Fungi can also act as mycoparasites or antagonists of other fungi, such as Hypomyces chrysospermus, which grows on bolete mushrooms.

text: Fungi can become the target of infection by mycoviruses.

text: Mycotoxins

text: Many fungi produce biologically active compounds, several of which are toxic to animals or plants and are therefore called mycotoxins. Of particular relevance to humans are mycotoxins produced by molds causing food spoilage, and poisonous mushrooms (see above). Particularly infamous are the lethal amatoxins in some Amanita mushrooms, and ergot alkaloids, which have a long history of causing serious epidemics of ergotism (St Anthony's Fire) in people consuming rye or related cereals contaminated with sclerotia of the ergot fungus, Claviceps purpurea.[181] Other notable mycotoxins include the aflatoxins, which are insidious liver toxins and highly carcinogenic metabolites produced by certain Aspergillus species often growing in or on grains and nuts consumed by humans, ochratoxins, patulin, and trichothecenes (e.g., T-2 mycotoxin) and fumonisins, which have significant impact on human food supplies or animal livestock.[182]

text: Mycotoxins are secondary metabolites (or natural products), and research has established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi.[30] Mycotoxins may provide fitness benefits in terms of physiological adaptation, competition with other microbes and fungi, and protection from consumption (fungivory).[183][184] Many fungal secondary metabolites (or derivatives) are used medically, as described under Human Use below.

text: Pathogenic mechanisms

text: Ustilago maydis is a pathogenic plant fungus that causes smut disease in maize and teosinte. Plants have evolved efficient defense systems against pathogenic microbes such as U. maydis. A rapid defense reaction after pathogen attack is the oxidative burst where the plant produces reactive oxygen species at the site of the attempted invasion. U. maydis can respond to the oxidative burst with an oxidative stress response, regulated by the gene YAP1. The response protects U. maydis from the host defense, and is necessary for the pathogen’s virulence.[185] Furthermore, U. maydis has a well-established recombinational DNA repair system which acts during mitosis and meiosis.[186] The system may assist the pathogen in surviving DNA damage arising from the host plant’s oxidative defensive response to infection.[187]

text: Cryptococcus neoformans is an encapsulated yeast that can live in both plants and animals. C. neoformans usually infects the lungs, where it is phagocytosed by alveolar macrophages.[188] Some C. neoformans can survive inside macrophages, which appears to be the basis for latency, disseminated disease, and resistance to antifungal agents. One mechanism by which C. neoformans survives the hostile macrophage environment is by up-regulating the expression of genes involved in the oxidative stress response.[188] Another mechanism involves meiosis. The majority of C. neoformans are mating "type a". Filaments of mating "type a" ordinarily have haploid nuclei, but they can become diploid (perhaps by endoduplication or by stimulated nuclear fusion) to form blastospores. The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed.[189] This process is referred to as monokaryotic fruiting. this process requires a gene called DMC1, which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous chromosome pairing during meiosis and repair of DNA double-strand breaks. Thus, C. neoformans can undergo a meiosis, monokaryotic fruiting, that promotes recombinational repair in the oxidative, DNA damaging environment of the host macrophage, and the repair capability may contribute to its virulence.[187][189]

text: Human use

text: The human use of fungi for food preparation or preservation and other purposes is extensive and has a long history. Mushroom farming and mushroom gathering are large industries in many countries. The study of the historical uses and sociological impact of fungi is known as ethnomycology. Because of the capacity of this group to produce an enormous range of natural products with antimicrobial or other biological activities, many species have long been used or are being developed for industrial production of antibiotics, vitamins, and anti-cancer and cholesterol-lowering drugs. More recently, methods have been developed for genetic engineering of fungi,[190] enabling metabolic engineering of fungal species. For example, genetic modification of yeast species[191]—which are easy to grow at fast rates in large fermentation vessels—has opened up ways of pharmaceutical production that are potentially more efficient than production by the original source organisms.[192]

text: Therapeutic uses

text: Modern chemotherapeutics

text: Many species produce metabolites that are major sources of pharmacologically active drugs. Particularly important are the antibiotics, including the penicillins, a structurally related group of β-lactam antibiotics that are synthesized from small peptides. Although naturally occurring penicillins such as penicillin G (produced by Penicillium chrysogenum) have a relatively narrow spectrum of biological activity, a wide range of other penicillins can be produced by chemical modification of the natural penicillins. Modern penicillins are semisynthetic compounds, obtained initially from fermentation cultures, but then structurally altered for specific desirable properties.[193] Other antibiotics produced by fungi include: ciclosporin, commonly used as an immunosuppressant during transplant surgery; and fusidic acid, used to help control infection from methicillin-resistant Staphylococcus aureus bacteria.[194] Widespread use of antibiotics for the treatment of bacterial diseases, such as tuberculosis, syphilis, leprosy, and others began in the early 20th century and continues to date. In nature, antibiotics of fungal or bacterial origin appear to play a dual role: at high concentrations they act as chemical defense against competition with other microorganisms in species-rich environments, such as the rhizosphere, and at low concentrations as quorum-sensing molecules for intra- or interspecies signaling.[195] Other drugs produced by fungi include griseofulvin isolated from Penicillium griseofulvum, used to treat fungal infections,[196] and statins (HMG-CoA reductase inhibitors), used to inhibit cholesterol synthesis. Examples of statins found in fungi include mevastatin from Penicillium citrinum and lovastatin from Aspergillus terreus and the oyster mushroom.[197] Fungi produce compounds that inhibit viruses[198][199] and cancer cells.[200][201] Specific metabolites, such as polysaccharide-K, ergotamine, and β-lactam antibiotics, are routinely used in clinical medicine. The shiitake mushroom is a source of lentinan, a clinical drug approved for use in cancer treatments in several countries, including Japan.[202][203] In Europe and Japan, polysaccharide-K (brand name Krestin), a chemical derived from Trametes versicolor, is an approved adjuvant for cancer therapy.[204]

text: Traditional and folk medicine

text: Certain mushrooms enjoy usage as therapeutics in folk medicines, such as Traditional Chinese medicine. Notable medicinal mushrooms with a well-documented history of use include Agaricus subrufescens,[200][205] Ganoderma lucidum,[206] and Ophiocordyceps sinensis.[207]

text: Cultured foods

text: Baker's yeast or Saccharomyces cerevisiae, a unicellular fungus, is used to make bread and other wheat-based products, such as pizza dough and dumplings.[208] Yeast species of the genus Saccharomyces are also used to produce alcoholic beverages through fermentation.[209] Shoyu koji mold (Aspergillus oryzae) is an essential ingredient in brewing Shoyu (soy sauce) and sake, and the preparation of miso,[210] while Rhizopus species are used for making tempeh.[211] Several of these fungi are domesticated species that were bred or selected according to their capacity to ferment food without producing harmful mycotoxins (see below), which are produced by very closely related Aspergilli.[212] Quorn, a meat substitute, is made from Fusarium venenatum.[213]

text: In food

text: Edible mushrooms include commercially raised and wild-harvested fungi. Agaricus bisporus, sold as button mushrooms when small or Portobello mushrooms when larger, is the most widely cultivated species in the West, used in salads, soups, and many other dishes. Many Asian fungi are commercially grown and have increased in popularity in the West. They are often available fresh in grocery stores and markets, including straw mushrooms (Volvariella volvacea), oyster mushrooms (Pleurotus ostreatus), shiitakes (Lentinula edodes), and enokitake (Flammulina spp.).[214]

text: Many other mushroom species are harvested from the wild for personal consumption or commercial sale. Milk mushrooms, morels, chanterelles, truffles, black trumpets, and porcini mushrooms (Boletus edulis) (also known as king boletes) demand a high price on the market. They are often used in gourmet dishes.[215]

text: Certain types of cheeses require inoculation of milk curds with fungal species that impart a unique flavor and texture to the cheese. Examples include the blue color in cheeses such as Stilton or Roquefort, which are made by inoculation with Penicillium roqueforti.[216] Molds used in cheese production are non-toxic and are thus safe for human consumption; however, mycotoxins (e.g., aflatoxins, roquefortine C, patulin, or others) may accumulate because of growth of other fungi during cheese ripening or storage.[217]

text: Poisonous fungi

text: Many mushroom species are poisonous to humans, with toxicities ranging from slight digestive problems or allergic reactions as well as hallucinations to severe organ failures and death. Genera with mushrooms containing deadly toxins include Conocybe, Galerina, Lepiota, and, the most infamous, Amanita.[218] The latter genus includes the destroying angel (A. virosa) and the death cap (A. phalloides), the most common cause of deadly mushroom poisoning.[219] The false morel (Gyromitra esculenta) is occasionally considered a delicacy when cooked, yet can be highly toxic when eaten raw.[220] Tricholoma equestre was considered edible until it was implicated in serious poisonings causing rhabdomyolysis.[221] Fly agaric mushrooms (Amanita muscaria) also cause occasional non-fatal poisonings, mostly as a result of ingestion for its hallucinogenic properties. Historically, fly agaric was used by different peoples in Europe and Asia and its present usage for religious or shamanic purposes is reported from some ethnic groups such as the Koryak people of north-eastern Siberia.[222]

text: As it is difficult to accurately identify a safe mushroom without proper training and knowledge, it is often advised to assume that a wild mushroom is poisonous and not to consume it.[223][224]

text: Pest control

text: In agriculture, fungi may be useful if they actively compete for nutrients and space with pathogenic microorganisms such as bacteria or other fungi via the competitive exclusion principle,[225] or if they are parasites of these pathogens. For example, certain species may be used to eliminate or suppress the growth of harmful plant pathogens, such as insects, mites, weeds, nematodes, and other fungi that cause diseases of important crop plants.[226] This has generated strong interest in practical applications that use these fungi in the biological control of these agricultural pests. Entomopathogenic fungi can be used as biopesticides, as they actively kill insects.[227] Examples that have been used as biological insecticides are Beauveria bassiana, Metarhizium spp, Hirsutella spp, Paecilomyces (Isaria) spp, and Lecanicillium lecanii.[228][229] Endophytic fungi of grasses of the genus Neotyphodium, such as N. coenophialum, produce alkaloids that are toxic to a range of invertebrate and vertebrate herbivores. These alkaloids protect grass plants from herbivory, but several endophyte alkaloids can poison grazing animals, such as cattle and sheep.[230] Infecting cultivars of pasture or forage grasses with Neotyphodium endophytes is one approach being used in grass breeding programs; the fungal strains are selected for producing only alkaloids that increase resistance to herbivores such as insects, while being non-toxic to livestock.[231]

text: Bioremediation

text: Certain fungi, in particular "white rot" fungi, can degrade insecticides, herbicides, pentachlorophenol, creosote, coal tars, and heavy fuels and turn them into carbon dioxide, water, and basic elements.[232] Fungi have been shown to biomineralize uranium oxides, suggesting they may have application in the bioremediation of radioactively polluted sites.[233][234][235]

text: Model organisms

text: Several pivotal discoveries in biology were made by researchers using fungi as model organisms, that is, fungi that grow and sexually reproduce rapidly in the laboratory. For example, the one gene-one enzyme hypothesis was formulated by scientists using the bread mold Neurospora crassa to test their biochemical theories.[236] Other important model fungi are Aspergillus nidulans and the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, each of which with a long history of use to investigate issues in eukaryotic cell biology and genetics, such as cell cycle regulation, chromatin structure, and gene regulation. Other fungal models have more recently emerged that address specific biological questions relevant to medicine, plant pathology, and industrial uses; examples include Candida albicans, a dimorphic, opportunistic human pathogen,[237] Magnaporthe grisea, a plant pathogen,[238] and Pichia pastoris, a yeast widely used for eukaryotic protein production.[239]

text: Others

text: Fungi are used extensively to produce industrial chemicals like citric, gluconic, lactic, and malic acids,[240] and industrial enzymes, such as lipases used in biological detergents,[241] cellulases used in making cellulosic ethanol[242] and stonewashed jeans,[243] and amylases,[244] invertases, proteases and xylanases.[245] Several species, most notably Psilocybin mushrooms (colloquially known as magic mushrooms), are ingested for their psychedelic properties, both recreationally and religiously.


document_title: Red-eared slider

question_text: when do red ear slider turtles lay eggs

question_tokens: when do red ear slider turtles lay eggs

root

text: Red-eared slider

text: Name[edit]

text: Red-eared sliders get their name from the small red stripe around their ears.. The "slider" in their name comes from their ability to slide off rocks and logs and into the water quickly. This species was previously known as Troost's turtle in honor of an American herpetologist; Trachemys scripta troostii is now the scientific name for another subspecies, the Cumberland slider.

tag: p

text: Taxonomy[edit]

text: The red-eared slider belongs to the order Testudines, which contains about 250 turtle species. It is a subspecies of Trachemys scripta. They were previously classified under the name Chrysemys scripta elegans.

text: The species Trachemys scripta contains three subspecies: T. s. elegans (red-eared slider), T. s. scripta (yellow-bellied slider), and T. s. troostii (Cumberland slider).[5]

text: Description[edit]

text: The carapace of this species can reach more than 40 cm (16 in) in length, but the average length ranges from 15 to 20 cm (6 to 8 in).[6] The females of the species are usually larger than the males. They typically live between 20 and 30 years, although some individuals have lived for more than 40 years.[7] Their life expectancy is shorter when they are kept in captivity.[8] The quality of their living environment has a strong influence on their lifespans and well being.

text: These turtles are poikilotherms, meaning they are unable to regulate their body temperatures independently; they are completely dependent on the temperature of their environment.[2] For this reason, they need to sunbathe frequently to warm themselves and maintain their body temperatures.

text: The shell is divided into two sections: the upper or dorsal carapace, and the lower, ventral carapace or plastron.[2] The upper carapace consists of the vertebral scutes, which form the central, elevated portion; pleural scutes that are located around the vertebral scutes; and then the marginal scutes around the edge of the carapace. The rear marginal scutes are notched. The scutes are bony keratinous elements. The carapace is oval and flattened (especially in the male) and has a weak keel that is more pronounced in the young.[9] The color of the carapace changes depending on the age of the turtle. The carapace usually has a dark green background with light and dark, highly variable markings. In young or recently hatched turtles, it is leaf green and gets slightly darker as a turtle gets older, until it is a very dark green, and then turns a shade between brown and olive green. The plastron is always a light yellow with dark, paired, irregular markings in the centre of most scutes. The plastron is highly variable in pattern. The head, legs, and tail are green with fine, irregular, yellow lines. The whole shell is covered in these stripes and markings that aid in camouflaging an individual.

text: Turtles also have a complete skeletal system, with partially webbed feet that help them to swim and that can be withdrawn inside the carapace along with the head and tail. The red stripe on each side of the head distinguishes the red-eared slider from all other North American species and gives this species its name, as the stripe is located behind the eyes where their (external) ears would be. These stripes may lose their color over time.[8] Some individuals can also have a small mark of the same color on the top of their heads. The red-eared slider does not have a visible outer ear or an external auditory canal; instead, it relies on a middle ear entirely covered by a cartilaginous tympanic disc.[10]

text: The main internal organs of these reptiles are the lungs, heart, stomach, liver, intestines, and the urinary bladder. A cloaca serves both excretory and reproductive functions.

text: Sexual dimorphism[edit]

text: Some dimorphism exists between males and females.[11]

text: Red-eared slider young look practically identical regardless of their sex, making it difficult to determine their sex. However, there is another method to determine their sex, by inspecting the markings under their carapace. These markings will fade as the turtles age. It is much easier to distinguish the sex of adults, as the shells of mature males are smaller than those of females.[12] Male red-eared sliders reach sexual maturity when their carapaces' diameters measure 10 cm (3.9 in) and females reach maturity when their carapaces measure 15 cm. Both male and females reach sexual maturity at five to six years. The male is normally smaller than the female, although this parameter is sometimes difficult to apply as individuals being compared could be of different ages.

text: Males have longer claws on their front feet than the females; this helps them to hold on to a female during mating and is used during courtship displays.[13] The male's tail is thicker and longer, it has a dark coloured retractable sexual organ known as their penis, inside the tail. Typically, the cloacal opening of the female is at or under the rear edge of the carapace, while the male's opening occurs beyond the edge of the carapace. The male's plastron is slightly concave, while that of the female is completely flat. The male's concave plastron also helps to stabilize the male on the female's carapace during mating.[14] Older males can sometimes have a dark greyish-olive green melanistic coloration, with very subdued markings. The red stripe on the sides of the head may be difficult to see or be absent. The female's appearance is substantially the same throughout her life.

text: Distribution and habitat[edit]

text: The red-eared slider originated from the area around the Mississippi River and the Gulf of Mexico, in warm climates in the southeastern United States. Their native areas range from the southeast of Colorado to Virginia and Florida. In nature, they inhabit areas with a source of still, warm water, such as ponds, lakes, swamps, creeks, streams, or slow-flowing rivers. They live in areas of calm water where they are able to leave the water easily by climbing onto rocks or tree trunks so they can warm up in the sun. Individuals are often found sunbathing in a group or even on top of each other. They also require abundant aquatic plants, as these are the adults' main food, although they are omnivores.[15] Turtles in the wild always remain close to water unless they are searching for a new habitat or when females leave the water to lay their eggs.

text: Owing to their popularity as pets, red-eared sliders have been released or escaped into the wild in many parts of the world.[16] The turtle is considered one of the world’s worst invasive species.[17] Feral populations are now found in Australia, Europe, South Africa, the Caribbean Islands, Israel, Bahrain, the Mariana Islands, Guam, and southeast and far-east Asia.[18][19] In Australia, it is illegal for members of the public to import, keep, trade, or release red-eared sliders, as they are regarded as an invasive species[20] - see below. Their import has been banned by the European Union[21] as well as specific EU member countries.[22] In 2015 Japan announced it was planning to ban the import of red-eared sliders, but it would probably not take effect until 2020.[23] Invasive red-eared sliders cause negative impacts in the ecosystems they occupy because they have certain advantages over the native populations, such as a lower age at maturity, higher fecundity rates, and larger body size, which gives them a competitive advantage at basking and nesting sites, as well as when exploiting food resources.[24] They also transmit diseases and displace the other turtle species with which they compete for food and breeding space.[25]

text: Behavior[edit]

text: Red-eared sliders are almost entirely aquatic, but as they are cold-blooded, they leave the water to sunbathe to regulate their temperature.

text: Hibernation[edit]

text: Red Eared Sliders do not hibernate, but actually brumate; while they become less active, they do occasionally rise to the surface for food or air. Brumation can occur to varying degrees. In the wild, red-eared sliders brumate over the winter at the bottoms of ponds or shallow lakes. They generally become inactive in October, when temperatures fall below 10 °C (50 °F).[9] During this time, the turtles enter a state of sopor, during which they do not eat or defecate, they remain nearly motionless, and the frequency of their breathing falls. Individuals usually brumate underwater, but they have also been found under banks and rocks, and in hollow stumps. In warmer winter climates, they can become active and come to the surface for basking. When the temperature begins to drop again, however, they quickly return to a brumation state. Sliders generally come up for food in early March to as late as the end of April.

text: During brumation, T. s. elegans can survive anaerobically for weeks, producing ATP from glycolysis. The turtle's metabolic rate drops dramatically, with heart rate and cardiac output dropping by 80% to minimise energy requirements.[26][27] The lactic acid produced is buffered by minerals in the shell, preventing acidosis.[28] Red-eared sliders kept captive indoors should not brumate.

text: Reproduction[edit]

text: Courtship and mating activities for red-eared sliders usually occur between March and July, and take place under water. During courtship, the male swims around the female and flutters or vibrates the back side of his long claws on and around her face and head, possibly to direct pheromones towards her.[29] The female swims toward the male and, if she is receptive, sinks to the bottom for mating. If the female is not receptive, she may become aggressive towards the male. Courtship can last 45 minutes, but mating takes only 10 minutes.[25]

text: On occasion, a male may appear to be courting another male, and when kept in captivity may also show this behaviour towards other household pets. Between male turtles, it could be a sign of dominance and may preclude a fight. Young turtles may carry out the courtship dance before they reach sexual maturity at five years of age, but they are unable to mate.[30]

text: After mating, the female spends extra time basking to keep her eggs warm.[30] She may also have a change of diet, eating only certain foods, or not eating as much as she normally would. A female can lay between two and 30 eggs depending on body size and other factors.[18] One female can lay up to five clutches in the same year, and clutches are usually spaced 12 to 36 days apart.[31] The time between mating and egg-laying can be days or weeks. The actual egg fertilization takes place during the egg-laying. This process also permits the laying of fertile eggs the following season, as the sperm can remain viable and available in the female's body in the absence of mating. During the last weeks of gestation, the female spends less time in the water and smells and scratches at the ground, indicating she is searching for a suitable place to lay her eggs. The female excavates a hole, using her hind legs, and lays her eggs in it.[32]

text: Incubation takes 59 to 112 days.[18] Late-season hatchlings may spend the winter in the nest and emerge when the weather warms in the spring. Just prior to hatching, the egg contains 50% turtle and 50% egg sac. A new hatchling breaks open its egg with its egg tooth, which falls out about an hour after hatching. This egg tooth never grows back. Hatchlings may stay inside their eggshells after hatching for the first day or two. If they are forced to leave the eggshell before they are ready, they will return if possible. When a hatchling decides to leave the shell, it still has a small sac protruding from its plastron. The yolk sac is vital and provides nourishment while visible, and several days later it will have been absorbed into the turtle's belly. The sac must be absorbed, and does not fall off. The split must heal on its own before the turtle is able to swim. The time between the egg hatching and water entry is 21 days.

text: Damage to or inordinate motion of the protruding egg yolk, enough to allow air into the turtle's body, results in death. This is the main reason for marking the top of turtle eggs if their relocation is required for any reason. An egg turned upside down will eventually terminate the embryo's growth by the sac smothering the embryo. If it manages to reach term, the turtle will try to flip over with the yolk sac, which would allow air into the body cavity and cause death. The other fatal danger is water getting into the body cavity before the sac is absorbed completely and while the opening has not completely healed yet.

text: The sex of red-eared sliders is determined by the incubation temperature during critical phases of the embryos' development. Only males are produced when eggs are incubated at temperatures of 22–27 °C (72–81 °F), whereas females develop at warmer temperatures.[33] Colder temperatures result in the death of the embryos.

text: Red-eared sliders as pets[edit]

text: Red-eared slider turtles are the world’s most commonly traded reptile, due to their relatively low price, small size and easy maintenance.[34][35] As with other turtles, tortoises, and box turtles, individuals that survive their first year or two can be expected to live generally around 30 years. But they are an infection risk, and when they mature they can inflict painful bites, which results in many being dumped into the wild with negative ecological, social and economic impacts.[36]

text: Infection risks and United States federal regulations on commercial distribution[edit]

text: Reptiles are asymptomatic (meaning they suffer no adverse side effects) carriers of bacteria of the genus Salmonella.[37] This has given rise to justifiable concerns given the many instances of infection of humans caused by the handling of turtles,[38] which has led to restrictions in the sale of red-eared sliders in the USA. A 1975 U.S. Food and Drug Administration (FDA) regulation bans the sale (for general commercial and public use) of both turtle eggs and turtles with a carapace length of less than 4 in (10 cm). This regulation comes under the Public Health Service Act, and is enforced by the FDA in cooperation with state and local health jurisdictions. The ban was enacted because of the public health impact of turtle-associated salmonellosis. Turtles and turtle eggs found to be offered for sale in violation of this provision are subject to destruction in accordance with FDA procedures. A fine of up to $1,001 and/or imprisonment for up to one year is the penalty for those who refuse to comply with a valid final demand for destruction of such turtles or their eggs.[39] Many stores and flea markets still sell small turtles due to an exception in the FDA regulation which allows turtles under 4 in (10 cm) to be sold "for bona fide scientific, educational, or exhibition purposes, other than use as pets."[40] As with many other animals and inanimate objects, the risk of Salmonella exposure can be reduced by following basic rules of cleanliness. Small children must be taught to wash their hands immediately after they finish playing with the turtle, feeding it, or changing its water.

text: US state law[edit]

text: Some states have other laws and regulations regarding possession of red-eared sliders because they can be an invasive species where they are not native and have been introduced through the pet trade. Now, it is illegal in Florida to sell any wild-type red-eared slider, as they interbreed with the local yellow-bellied slider population — Trachemys scripta scripta is another subspecies of pond sliders, and hybrids typically combine the markings of the two subspecies. However, unusual color varieties such as albino and pastel red-eared sliders, which are derived from captive breeding, are still allowed for sale.[41]

text: An invasive species in Australia[edit]

text: In Australia, breeding populations have been found in New South Wales and Queensland, and individual turtles have been found in the wild in Victoria, the Australian Capital Territory and Western Australia.[42]

text: Red-eared slider turtles are considered a significant threat to native turtle species - they mature more quickly, grow larger, produce more offspring and are more aggressive.[42] Numerous studies provide evidence that red-eared slider turtles can out-compete native turtles for food and nesting and basking sites.[43] Because red-eared slider turtles eat plants as well as animals, they could also have a negative impact on a range of native aquatic species, including rare frogs.[44] There is also a significant risk that red-eared slider turtles will transfer diseases and parasites to native reptile species. There is evidence that a malaria-like parasite was spread to two wild turtle populations in Lane Cove River, Sydney.[45]

text: Social and economic costs are also likely to be substantial. The Queensland government has invested close to $1 million AUD in eradication programs to date.[42] As outlined in the foregoing section, the turtle may also have significant public health costs due to the impacts of turtle-associated salmonella on human health. Outbreaks in multiple states and fatalities in children, associated with handling salmonella-infected turtles, have been recorded in the USA.[46] Salmonella can also spread to humans when turtles contaminate drinking water.[47]

text: There have been varying degrees of action by state governments to date, ranging from ongoing eradication efforts by the Queensland government to very little action by the government of New South Wales.[48] Experts have ranked the species as high priority for management in Australia and are calling for a national prevention and eradication strategy, including a concerted education and compliance program to stop the illegal trade, possession and release of slider turtles.[49]

text: In popular culture[edit]

text: Within the second volume of the Tales of the Teenage Mutant Ninja Turtles, the popular comic book heroes were revealed as specimens of the red-eared slider. The popularity of the Turtles led to a craze for keeping them as pets in Great Britain, and subsequent ecological havoc as turtles were accidentally or deliberately released into the wild.[50]


document_title: QT interval

question_text: what are the upper limits of normal for the qtc

text: QT interval

text: Correction for heart rate[edit]

text: Like the R–R interval, the QT interval is dependent on the heart rate in an obvious way (i.e., the faster the heart rate, the shorter the R–R interval and QT interval) and may be adjusted to improve the detection of patients at increased risk of ventricular arrhythmia. Modern computer-based ECG machines can easily calculate a corrected QT (QTc), but this correction may not aid in the detection of patients at increased risk of arrhythmia, as there are a number of different correction formulas.

text: Bazett's formula[edit]

text: The most commonly used QT correction formula is the Bazett's formula,[1] named after physiologist Henry Cuthbert Bazett (1885-1950),[2] calculating the heart rate-corrected QT interval (QTcB).

text:
Bazett's formula is based on observations from a study in 1920.
Bazett's formula is given as:

text:
Q
T
c
B
=

Q
T

R
R

{\displaystyle QTcB={QT \over {\sqrt {RR}}}}

text: where QTcB is the QT interval corrected for heart rate, and RR is the interval from the onset of one QRS complex to the onset of the next QRS complex, measured in seconds, often derived from the heart rate (HR) as 60/HR. Here QT is measured in milliseconds, therefore the result will be given in seconds per square root of milliseconds.[3] This non-linear QT correction formula is generally not considered accurate, as it over-corrects at high heart rates and under-corrects at low heart rates.[4] Bazett's correction formula is one of the most suitable QT correction formula for neonates.[5]

text: Fridericia's formula[edit]

text: Fridericia[6] had proposed an alternative correction formula using the cube-root of RR.

text:
Q
T
c
F
=

Q
T

R
R

3

{\displaystyle QTcF={QT \over {\sqrt[{3}]{RR}}}}

text: Sagie's formula[edit]

text: The Framingham correction, also called as Sagie's formula based on the Framingham Heart Study, which used long-term cohort data of over 5,000 subjects, is considered a better[7] method.[8]

text:
Q
T
l
c
=
1000
(

Q
T

/

1000
+
0.154
(
1
−
R
R
)

)

{\displaystyle QTlc=1000({QT/1000+0.154(1-RR)})}

text: Again, here QT and QTlc are in milliseconds and RR is measured in seconds.

text: Comparison of corrections[edit]

text: A recent retrospective study suggests that Fridericia's method and the Framingham method may produce results most useful for stratifying the 30-day and 1-year risks of mortality.[7]

text: Definitions of normal QTc vary from being equal to or less than 0.40 s (≤400 ms),[9] 0.41s (≤410ms),[10] 0.42s (≤420ms)[11] or 0.44s (≤440ms).[12] For risk of sudden cardiac death, "borderline QTc" in males is 431–450 ms; and, in females, 451–470 ms. An "abnormal" QTc in males is a QTc above 450 ms; and, in females, above 470 ms.[13]

text: If there is not a very high or low heart rate, the upper limits of QT can roughly be estimated by taking QT=QTc at a heart rate of 60 beats per minute (bpm), and subtracting 0.02s from QT for every 10 bpm increase in heart rate. For example, taking normal QTc ≤ 0.42 s, QT would be expected to be 0.42 s or less at a heart rate of 60 bpm. For a heart rate of 70 bpm, QT would roughly be expected to be equal to or below 0.40 s. Likewise, for 80 bpm, QT would roughly be expected to be equal to or below 0.38 s.[9]

text: Measurement[edit]

text: The QT interval is most commonly measured in lead II for evaluation of serial ECGs, with leads I and V5 being comparable alternatives to lead II. Leads III, aVL and V1 are generally avoided for measurement of QT interval.[14] The accurate measurement of the QT interval is subjective[15] because the end of the T wave is not always clearly defined and usually merges gradually with the baseline. QT interval in an ECG complex can be measured manually by different methods, such as the threshold method, in which the end of the T wave is determined by the point at which the component of the T wave merges with the isoelectric baseline, or the tangent method, in which the end of the T wave is determined by the intersection of a tangent line extrapolated from the T wave at the point of maximum downslope to the isoelectric baseline.[16]

text: With the increased availability of digital ECGs with simultaneous 12-channel recording, QT measurement may also be done by the 'superimposed median beat' method. In the superimposed median beat method, a median ECG complex is constructed for each of the 12 leads. The 12 median beats are superimposed on each other and the QT interval is measured either from the earliest onset of the Q wave to the latest offset of the T wave or from the point of maximum convergence for the Q wave onset to the T wave offset.[17]

text: Abnormal intervals[edit]

text: Prolonged QTc causes premature action potentials during the late phases of depolarization. This increases the risk of developing ventricular arrhythmias, including fatal ventricular fibrillation.[18] Higher rates of prolonged QTc are seen in females, older patients, high systolic blood pressure or heart rate, and short stature.[19] Prolonged QTc is also associated with EKG findings called Torsades de Pointes, which are known to degenerate into ventricular fibrillation, associated with higher mortality rates. There are many causes of prolonged QT intervals, acquired causes being more common than genetic.[20]

text: Genetic causes[edit]

text: An abnormally prolonged QT interval could be due to long QT syndrome, whereas an abnormally shortened QT interval could be due to short QT syndrome.

text: The QTc length is associated with variations in the NOS1AP gene.[21] The autosomal recessive syndrome of Jervell and Lange-Nielsen is characterized by a prolonged QTc interval in conjunction with sensorineural hearing loss.

text: Due to adverse drug reactions[edit]

text: Prolongation of the QT interval may be due to an adverse drug reaction.[22] Many drugs, such as haloperidol,[23] vemurafenib, ziprasidone, methadone[24] and sertindole,[25] can prolong the QT interval. Some antiarrhythmic drugs, like amiodarone or sotalol, work by getting a pharmacological QT prolongation. Also, some second-generation antihistamines, such as astemizole, have this effect. In addition, high blood alcohol concentrations prolong the QT interval.[26] A possible interaction between selective serotonin reuptake inhibitors and thiazide diuretics is associated with QT prolongation.[27] Macrolide antibiotics are also suspected to prolong the QT interval, after it was discovered recently that azithromycin is associated with an increase in cardiovascular death.[28]

text: Due to pathological conditions[edit]

text: Hypothyroidism, a condition of low function of the thyroid gland, can cause QT prolongation at the electrocardiogram.  Acute hypocalcemia causes prolongation of the QT interval, which may lead to ventricular dysrhythmias.

text: A shortened QT can be associated with hypercalcemia.[29]

text: Use in drug approval studies[edit]

text: Since 2005, the FDA and European regulators have required that nearly all new molecular entities be evaluated in a Thorough QT (TQT) study to determine a drug's effect on the QT interval.[30] The TQT study serves to assess the potential arrhythmia liability of a drug.  Traditionally, the QT interval has been evaluated by having an individual human reader measure approximately nine cardiac beats per clinical timepoint.  However, a number of recent drug approvals have used a highly automated approach, blending automated software algorithms with expert human readers reviewing a portion of the cardiac beats, to enable the assessment of significantly more beats per timepoint in order to improve precision and reduce cost.[31] As the pharmaceutical industry has gained experience in performing TQT studies, it has also become evident that traditional QT correction formulas such as QTcF, QTcB, and QTcLC may not always be suitable for evaluation of drugs impacting autonomic tone.[32]

text: As a predictor of mortality[edit]

text: Electrocardiography is a safe and noninvasive tool that can be used to identify those with a higher risk of mortality. In the general population, there has been no consistent evidence that prolonged QTc interval in isolation is associated with an increase in mortality from cardiovascular disease.[33] However, several studies[which?] have examined prolonged QT interval as a predictor of mortality for diseased subsets of the population.

text: Rheumatoid arthritis[edit]

text:
Rheumatoid arthritis is the most common inflammatory arthritis.[34] Studies have linked rheumatoid arthritis with increased death from cardiovascular disease.[34]
In a 2014 study,[18] Panoulas et al. found a 50 ms increase in QTc interval increased the odds of all-cause mortality by 2.17 in patients with rheumatoid arthritis. Patients with the highest QTc interval (> 424 ms) had higher mortality than those with a lower QTc interval. The association was lost when calculations were adjusted for C-reactive protein levels. The researchers proposed that inflammation prolonged the QTc interval and created arrhythmias that were associated with higher mortality rates. However, the mechanism by which C-reactive protein is associated with the QTc interval is still not understood.

text: Type 1 diabetes[edit]

text: Compared to the general population, type 1 diabetes may increase the risk of mortality, due largely to an increased risk of cardiovascular disease.[19][35] Almost half of patients with type 1 diabetes have a prolonged QTc interval (> 440 ms).[19] Diabetes with a prolonged QTc interval was associated with a 29% mortality over 10 years in comparison to 19% with a normal QTc interval.[19] Anti-hypertensive drugs increased the QTc interval, but were not an independent predictor of mortality.[19]

text: Type 2 diabetes[edit]

text:
QT interval dispersion (QTd) is the maximum QT interval minus the minimum QT interval, and is linked with ventricular repolarization.[36] A QTd over 80 ms is considered abnormally prolonged.[37] Increased QTd is associated with mortality in type 2 diabetes.[37]
QTd is a better predictor of cardiovascular death than QTc, which was unassociated with mortality in type 2 diabetes.[37] QTd higher than 80 ms had a relative risk of 1.26 of dying from cardiovascular disease compared to a normal QTd.


document_title: Railway Recruitment Control Board

question_text: total number of railway recruitment board in india

text: Railway Recruitment Control Board

text: Objectives[edit]

text:
Formulation of policy in regard to recruitment procedures.
To monitor the activities of all Railway Recruitment Boards (RRBs) including expenditure incurred for recruitment.
To evaluate the performance of RRB's and advise them on priorities as required.
To organise a management information system for monitoring work done by RRB's.

tag: ul

text: Railway Recruitment Boards[edit]

text: Overview[edit]

text: Railway Recruitment Boards are organisations under the Government of India that manage the appointment of new employees to work in Indian railways.[3] There are 21 boards situated in different parts of India:

text:
Ahemadabad
Ajmer
Allahabad
Banglore
Bhopal
Bhubaneswar
Bilaspur
Chandigarh
Chennai
Gorakhpur
Guwahati
Jammu and Kashmir
Kolkata
Malda
Mumbai
Muzaffarpur
Patna
Ranchi
Secunderabad
Siliguri
Thiruvantha-puram

text: History[edit]

text: In 1942, a Service Commission with a Chairman and two members was established for recruitment of Subordinate Staff on the then North West Railway was known as Railway Service Commission.

text: Developments[edit]

text: In 1945, the Services Commissions were set up at Bombay, Calcutta, Madras and Lucknow. In 1948, the Indian Railway Enquiry Committee reviewed working of commissions.In 1949, due to financial constraints a ban was imposed on recruitments on Indian Railways thus numbers of commissions was reduced to one centrally located at Bombay.In 1953-54 when Economic conditions of Indian Railway improved, four service commission were again set up at Bombay, Madras, Allahabad and Calcutta. In 1956, the Estimates committee generally approved the method of recruitment by the constitution of the Railway Service Commissions. In 1983, to cater to the needs of areas which were being neglected due to locations of the existing commissions, seven more commissions were set up viz, at Ahmedabad, Ajmer, Bhopal, Bhuvneshwar, Chandigarh, Jammu and Srinagar with sitting at Leh and Trivendrum. In 1984 two more service commissions were set up at Malda and Gorakhpur. In January, 1985 Railway Service Commissions have been renamed as Railway Recruitment Board (RRB). At present 19 Railway Recruitment Boards are functioning.[4]

text: ALP & Technician[edit]

text: Railway Recruitment Board (RRB) conducts computer based examination for recruitment of ALP & Technician posts. RRB has released centralized notification 01/2018 for total 26502 vacancies.[5]. RRB ALP & Technician Recruitment 2018 will be held in two stages followed by Aptitude Test (if applicable) and Document Verification. First Stage CBT is scheduled to be held in the month of April and May 2018.

text: RRB NTPC[edit]

text: Railway Recruitment Board (RRB) conducts Non Technical Popular Categories (NTPC) exam to recruit Commercial apprentice, Goods guard, Traffic Apprentice, Traffic Assistant, Assistant Station Master etc. all over India. After releasing answer keys; rrb ntpc declares result after some months. Which can be checked on different 21 official zone websites.[6]